It is well recognized that proper and uniform spacing of seed in the furrow is essential to maximizing crop yield. Recent advances in metering technology have resulted in seed meters capable of singulating seed extremely well in field planting conditions. However, once the seed is dispensed from the seed meter, various factors can operate on the seed which can effect the ultimate spacing of the seed in the furrow. One such “post-seed-discharge” factor effecting seed spacing in the furrow is the manner in which sequentially released seeds travel through the seed tube.
It has been found that once seeds are dispensed into the seed tube, sequentially released seeds may travel through the seed tube at different rates depending on the amount and type of contact the seeds have with the sidewalls of the seed tube. In some instances, a later sequentially dispensed seed may even pass a previously dispensed seed in the seed tube. For example, some seeds may quickly pass through the seed tube by free-fall substantially the entire length of the seed tube, only making brief contact or sliding contact with the forward curved wall of the seed tube before exiting the seed tube. Other seeds may pass more slowly through the seed tube by sliding along the curved forward wall of the seed tube substantially the entire length of the seed tube. Still other seeds may pass even more slowly through the seed tube as a result of bouncing and ricocheting off the walls of the seed tube substantially the whole length of the seed tube.
Several factors contribute to seeds experiencing different amounts and types of contact with the walls of the seed tube, thereby effecting seed spacing in the furrow. For example, as an agricultural planter traverses a field, surface irregularities in the field lead to momentary jostling, vibration or other positional shifting of the planter components, including the seed tubes. The desire to plant at ever increasing ground speeds compounds, these post-seed-discharge factors effecting accuracy and uniformity of seed spacing in the furrow.
With tests using high speed cameras, it was found that the amount of contact with the side walls of the seed tube that a seed experiences while traveling through the seed tube is greatly effected by the manner and position in which the seed enters the seed tube. The high speed camera footage revealed that if the seeds are dispensed to either side of the centerline of the seed tube, the seeds contact the side walls of the seed tube more frequently, than if the seeds are dispensed directly into the center of the tube. As previously discussed, it is important that all seeds pass through the seed tube at the same rate in order for the seed spacing to be maintained in the furrow corresponding to the seed discharge rate from the seed meter.
While the high speed camera footage simply confirms what seems a logical conclusion, no one has heretofore conceived of a means for accurately and consistently delivering and releasing seeds into the seed tube near its vertical centerline. The foregoing problem of delivering seed into the seed tube near its vertical centerline is a particular problem with planters using finger-type seed meters. Finger-type seed meters have been used on agricultural planters since the early 1970s, and continue to be the most widely used type of seed meter on planters in use today.
The overall structure and function of the finger-type seed meter has changed little from the original patented design disclosed in U.S. Pat. No. 3,552,601 to Hansen et al. (hereinafter “Hansen '601”). Improvements to certain components of the finger-type meter which improve the operation of the finger-pickup meter are disclosed in U.S. Pat. No. 6,269,758 to Sauder et al. and U.S. Pat. No. 6,729,249 to Sauder et al (hereinafter “Sauder '758” and “Sauder '249”, respectively).
Referring to FIGS. 1, 2 and 3 a conventional finger-type seed meter 30 as disclosed in Hansen '601, Sauder '758 or Sauder '249 is illustrated. The seed meter 30 cooperates with a seed belt housing assembly 34, which receives the seeds being sequentially discharged from the seed meter 30, and separately conveys the singulated seeds toward the seed tube 36 into which the seeds are released. While the seed belt housing assembly 34 serves its intended purpose of sequentially receiving seeds from the seed meter for release into the seed tube 36, the flighted seed belt 96 of the seed belt housing assembly 34 does not consistently dispense the seeds near the vertical axis of the seed tube 36. One of the reasons for the inconsistency is that the flight 97 of the seed belt 96 is typically approximately one inch in width, while the largest seeds typically planted with finger-type meters are corn or sunflower seeds with their largest dimension generally not exceeding ⅜ inch. Due to the disparity in the width of the flight 97 versus the seed, the position of the seed on the flight can vary nearly one inch. Thus, the area over which sequential seeds may enter the seed tube may vary by nearly an inch, or nearly ½ inch laterally on either side of the vertical centerline of the seed tube. As a result, the structure of the seed belt 96 as found in conventional seed belt housings 34, actually contributes to inaccurate seed spacing in the furrow.
Thus, there is a need in the agricultural industry for a seed belt which can replace the seed belts used with conventional seed belt housings but which overcomes the deficiencies associated with conventional seed belts. Similarly, there is a need for seed belts for use in any application where it is desired to accurately and consistently dispense seeds, whether into a seed tube or directly into a seed furrow.